package com.neusoft.elmboot.controller;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

/**
 * 
 * @author chens
 *
 */
@Controller
public class ValidateCodeController {

	@RequestMapping("/validatecode")
	public void getCode(HttpSession session, HttpServletResponse response) throws IOException {

		// 设置页面不缓存
		response.setHeader("Pragma", "No-cache");
		response.setHeader("Cache-Control", "no-cache");
		response.setDateHeader("Expires", 0);
		// 在内存中创建图象
		int width = 60, height = 20;
		BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
		// 获取图形上下文
		Graphics g = image.getGraphics();
		// 生成随机类
		Random random = new Random();
		// 设定背景色
		g.setColor(getRandColor(200, 250));
		g.fillRect(0, 0, width, height);
		// 设定字体
		g.setFont(new Font("Times New Roman", Font.PLAIN, 18));
		// 画边框
		// g.setColor(new Color());
		// g.drawRect(0,0,width-1,height-1);
		// 随机产生155条干扰线，使图象中的认证码不易被其它程序探测到
		g.setColor(getRandColor(160, 200));
		final int line = 155;
		for (int i = 0; i < line; i++) {
			int x = random.nextInt(width);
			int y = random.nextInt(height);
			int xl = random.nextInt(12);
			int yl = random.nextInt(12);
			g.drawLine(x, y, x + xl, y + yl);
		}
		// 取随机产生的认证码(4位数字)
		String sRand = "";
		final int count = 4;
		for (int i = 0; i < count; i++) {
			String rand = String.valueOf(random.nextInt(10));
			sRand += rand;
			// 将认证码显示到图象中
			// 调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成
			g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110)));
			g.drawString(rand, 13 * i + 6, 16);
		}
		// 将认证码存入SESSION
		session.setAttribute("rand", sRand);
		// 图象生效
		g.dispose();
		OutputStream output = response.getOutputStream();
		// 输出图象到页面
		ImageIO.write(image, "JPEG", response.getOutputStream());
		output.flush();

	}

	/**
	 * 给定范围获得随机颜色
	 * @param fc
	 * @param bc
	 * @return
	 */
	Color getRandColor(int fc, int bc) {
		final int line = 255;
		Random random = new Random();
		if (fc > line) {
			fc = 255;
		}
		if (bc > line) {
			bc = 255;
		}
		int r = fc + random.nextInt(bc - fc);
		int g = fc + random.nextInt(bc - fc);
		int b = fc + random.nextInt(bc - fc);
		return new Color(r, g, b);
	}

}
